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1851- 1900: Observations limited to widely scattered ships and shore observations. Instrumentation has large measurement errors and calibration is often questionable.
1900 – 1950: Increasing number of ships and the advent of aircraft observations, but aircraft have limited range and cieling. Shore observations start to become more technologically sophisticated. At end of period, the first computers appear. Instrumentation has acceptable errors and calibration is required.
1950 – 2000: Advent of satellite observations, aircraft have sufficient range to cover Most of Sargasso Sea, all of Gulf of Mexico and all of Caribbean, cielings high enough to make reasonable upper troposhere measurements on site. Automated shore measurements, digitized data, essentially unlimited data storage, computers and advanced algorithms and filters. Advanced gage R & R techniques understood (but underutilized).

Prior to recon flights, circa 1950, there was little way to tell the strength of an at-sea hurricane other than from a ship’s chance encounter with the eye of the storm. Those were rare. So, just how were those at-sea red dots determined for the two pre-1950 graphs?

Answer – they guessed the windspeed. And guessed and guessed and guessed and guessed and guessed some more and then guessed again.

Take note of the total plots for Cat 1,2 and compare to Cat 3,4,5. In the 1851-1900 period Cat 1, 2 plots are higher than the other two periods. Yet is way down in Cat 3,4,5 plots compared with the other periods. The only reasonable explanation I can find for this is lack of ship/shore communication. Ships caught in 3,4,5 may not have had a very high survival rate. Also, what captain isn’t going to steer away from the storm when encountering a severe one.

With 1851-1900 likely severely under-reported, I tend to think those 50 years were likely the worst of the last 150. Can’t prove it though.

The TD/TS coverage has increased dramatically as the years have passed.

I just extracted initial storm readings and final readings. So here are some figures to contemplate. With so many storms in the 1st 50 years not being detected until reaching hurricane strength, it seems more than likely that many storms went unrecorded.

There’s an old American TV sitcom named “I Love Lucy”. Sometimes Lucy had some ” ‘splainin to do”. I think that anyone choosing to use the historical storm count has some ‘splainin to do about the pattern changes.